Reversing valve



Feb. 12 119240 J. E. GREENSMITH REVERSING VALVE Original Filed April 19,192% 3 Sheets-Sheet 1 K w \ixull wwlr wlw nnlll mew): JamesE Greens/72%Feb, 12 9 1924.;

J.- E. GREENSMITH REVERSING VALVE Original Filed April 19. 1920 3.Sheets-Sheet 2 Fei'o. 12

J. E. GREENSMITH REVERS ING VALVE 3 Sheets-Sheet 3 JAMES E. GREENSMITH.OF BROOKLINE, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO BOSTON SCALE &MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORA- TION OFMASSACHUSETTS.

REVERSING VALVE.

Original application filed April 19, 1920, Serial No. 374,815. Dividedand this application filed January 13, 1921. Serial No. 437,068.

I To all whom it may concern:

Be it known that I, JAMES E. GREEN- SMITH, a citizen of the UnitedStates, residing at Brookline. in the county of Norfolk and State ofMassachusetts, have invented certain new and useful Improvements inReversing Valves, of which the following is a clear, full, and exactdescription.

This invention relates to reversing valves and with regard to certainmore specific features thereof to reversing valves adapted for use withfluid pressure operated machines.

The invention has for one of its objects to provide a highly balancedmechanism with a'minimum amount of friction between cooperating valveparts.

Another object of the invention is in the provision of simple andreliably operative means for effecting accurate registration of thedifl'erent valve ports. A

Still another object of the invention is to provide a simple andinexpensive device for effecting reversal of fluid flow, which means areactuated primarily by moving parts of the fluid pressure operatedmachine, but the final actuation of which means is independent of theaction of said moving parts.

Other objects will be in part obvious and in art pointed outparticularly hereinaften.

he invention, accordingly, consists in the various features ofconstruction, combination of elements and arrangements of parts, whichwill be exemplified by the construction hereinafter set forth and thescope of the application of which will be indicated by the appendedclaims:

This application is a division of one filed by me April 19, 1920, theserial number of i which is 374,815.

In the drawings, wherein is represented one of various possibleembodiments of the invention:

I Fig. 1 is a vertical longitudinal sectional view of a hydraulicgrinding machine showing the improved reversing valve mechanism. v Fig.2 is a view in front elevation of the exterior of the valve mechanismshown in Fig. 1.

i 3 is a view in cross section taken substantlally along the line 3-3 ofFig. 2.

Fig. 4 is a view in elevation of the valve body or-core, and

piston 2 which is moved back and forth in a cylinder 3 under theinfluence of fluid introduced under pressure at one or the other of thecylinder ends.

The valve mechanism comprises a housing in the form of a shortcylindrical tube 4 having a flange or annular lip 5 by which the tube issecured to the frame .1 through an opening 6 provided -in the front ofthe frame. A. closure plate 7 is attached to the rear'of the tube andthere is a front closure plate 8 formed with an extended sleeve 9 whichis secured against the forward partof the tube in the bell shapedopening provided by the junction of the flange and body of the housing.

The body of the housing contains a cylindrical cage 10 and within thiscage there is rotatively fitted a valve or core 11. The body of this.valve or core is in the form of a shell having two substantiallydiametri-- cally opposed ports 12 and 13 of long and narrowconfiguration. The exterior of -the core is cleared away intermediatetwo naring the ports 12 and 13, an area 17 which cooperates with anexhaust port 18 and an area 19 substantially at the top of the valvewhich is left for the purpose of assisting in securin a high degree ofvalve balance.

he valve cage 10 has two ports 20 and 21 corresponding in size and shapewith ports 12 and 13 of the valve or core, and the said valve ports areadapted respectively and alternately to register with the ports 20 and21 of the cage. The valve as shown in Figs. 1 and 5 is in neutralposition, shutting off the fluid from forward and rearward supply pipes22 and 23 of the c linder and closing an exhaust pipe 24. hould thevalve be turned to cause registration of the ports 12 and 20, the fluidwill pass from a supply pipe 25 through the interior of the hollow shellof the valve core, through port 12 of the valve core, port 20 of thevalve cage, forward cylinder supply pipe 22, to the forward end ofcylinder 3, whereupon piston 2 will be urged rearwardly and the toolcarrier in thesamedirection. It will be noted that when these two portsare in communication the port 13 of the valve core is moved out ofregistration with the port 21 of the valve cage which latter is incommunication with the rearward cylinder supply pipe 23. The raised areasurrounding the port 13 of the core is moved beyond port 21 of the cageso that fluid in the cylinder to the rear of the piston is permitted toexhaust through the rearward cylinder pipe 23, port 21, around theexterior of the valve core, pass ing by theraised area at the endsthereof, and discharging through the port 18 of the valve cage into anexhaust pipe 27.

To reverse the direction of flow of the liquid the valve core is rotatedto cause reg- This will permit the flow of fluid through motor.

the rearward cylinder supply pipe and exhaust of the fluid through theforward pipe around the valve core through the port 18 of the cage tothe exhaust pipe 27.

This improved valve construction provides a nicety of balance of thevalve parts.

- The fluid'pressure is distributed evenly inside and outside of thevalve. As the fluid used has a lubricating characteristic and flowsabout between the valve core and its cage, constant lubrication iseffected. The routing of the exterior of the valve leaving only the fewraised areas necessary to close, open or partition the ports, reducesfriction to a minimum.- The valve may be set in its different operativepositions by a movement through a very slightangular range. The balanceand consequent ease of operation obtained by this valve structurecontributes to the smooth and flexible operation of the machine underthe influence of the hydraulic Inasmuch as the tool carrier is intendedto be automatic in its reciprocatory feeding movement, and the reversalof its movement at each extremity is under its own control through themedium of the valve, it is highly advantageous to reduce the burden ofthe. valve operation to the lowest possible point. It will be pointedout in the following that the direct actuating means for the valve is aspring which operates a cam mechanism which in turn rotates the valvecore. By constructing the valve parts as specified, the friction is sogreatly in to the rear closure plate 7 of the valvehousing. From aninspection of Fig. 3 of the drawings it will be apparent that the fluidis discharged from the inlet pipe into the interior of the valve core 11passing through the registered ports. It finds its Way to one end or theother .of the cylinder according to which ports are in registration andthe fluid at the opposite end of the cylinder is exhausted throughanother portion of the valve and the exhaust pipe 27. It is only whenthe valve is moved to register one pair of ports as an inlet to one endof the cylinder that the exhaust passage through the valve is open. Theliquid in the exhaust end of the cylinder is confined therein exceptwhen the fluid is being supplied under pressure to the other end of thecylinder. In the exhaust pipe 27 there is provided a manually operablevalve '30 for regulating the rate of flow of the fluid through theexhaust and which consequently regulates the rate of movement of thepiston in the cylinder 3. The exhaust pipe discharges into a container(not shown) from which it is drawn by the pump and directed to the inletpipe 25.

An end thrust ball bearin 31 is provided between the valve core and t efront closure member of the valve housing, and a conduit 32 is providedin the forward end of the valve so as to permit'a portion of theoperating fluid to flow into a chamber 33 surrounding said bearing,thereby maintaining lOS it constantly lubricated. It will be apparentfrom an inspection of Fig. 3 that there is a slight space at the rear ofthe valve core between the rear edge of same and the rear closure 7. Soit will be seen that there is a distribution of the fluid under pressureat both ends of the valve core as well as within and around the same.

The operatingmechanism for the valve comprises a forwardly extendingstem 40 on the valve core which has a bearing in the sleeve 9 of thefront closure plate 8. Suitable packing is provided to prevent leakageof oil and this packing is held in place by a hollow screw member 41tapped into the forward part of the sleeve and being itself bored toserve as a part or continuation of the bearing for. the valve. Theforward front part of the closure member 8 of the valve mechanism is inthe shape of a short cylindrical boss and mounted on this boss for freerotative movement but held against longitudinal displacement thereon isa plate 42 having a central recession 43 from its upper edge, providinga yoke. The plate 42 carries two links 44 and 45 pivotally supportedforwardly thereof as shown clearly in Fig. 2. These links have theirfree ends equipped with cam rollers and 51 which are constrained tomovement towards one another by means of a spring 52 connected at eitherend to pins 53 and 54 projecting respectively from the rear wall of eachlink. An operating lever is pivotally mounted on the frame of themachine, the pivot being preferably near the top of the slideway for thetool' carriage. This lever has a short forward extension above its pivotproviding a handle 61 by which it may be operated. There is also journaled in the rear of the upward extension a roller 62 adapted to beabutted by actuating members or stops 63 and 64 which are adjustablyfixed on the tool carrier. The lever 60 has at its lower extremity aroller positioned within the recession 43 of the plate 42 and adapted tobear against one or the other of the side walls of the yoke accordinglyas the lever is pivotally moved in one direction or the other. At theforward extremity of the stem 40 of the valve there is fixed a cammember 71 having a depending arm 72. The said arm is formed with stopfaces 73 and 74 adapted to abut adjustable stops 7 5 and 76 provided onthe front of the valve housing and consequently in fixed relation withthe frame of the machine. is so shaped as to urge the rollers 50 and 51of the links on the plate 42 away from each other as the operatinghandle is moved from one extreme position toward the other. Thismovement of the links extends the spring 52 and when the handle hasreached a point predetermined as being near its opposite extremity ofmovement, points 77 and 78 of the cam member pass by the rollers 50 and51 respectively. and the spring 52 acts through these rollers on theopposite faces of the cam to. cause that member to move quickly to itsopposite extremity of movement. The cam member being, as before stated,fixed to the stem of the valve, carries the valve core through a rangeof angular movement which breaks communication between one set of portsand effects registration of the other set of ports.

The arm 7 2 of the cam member has at its lower end a spring detent 80which during the' automatic operationof the machine is lockedinoperative by the tongue and groove device indicated at 81 but whichmay be utilized to lock the valve in any one of the three desiredpositions. The actuating blocks 63 and 64 by which the handle isautomatically operated are applied to the tool carrying slide by meansof T bolt look ing devices, the heads of which are slidably adjustablein a T slot 85 extending longitudinally of the tool carrying slide. Bythis construction the actuatlng blocks may be The cam member 71 quicklyand conveniently moved to andv As many changes might be made in theabove construction and as many apparently widely different embodimentsof the invention might be made without departing from the scope thereof,it is intended that all matter contained in the foregoing description orshown in the accompanying drawings shall be interpreted as illustrativeand not in a limiting sense.

What I claim is:

1. In a machine of the character described, in combination, a cylinderhaving a port at each end, a piston in said cylinder, a reversing valve,said reversing valve 1neluding a cage having ports in communication withthe cylinder ports, a plug having ports adapted alternately tocommunicate with the ports of said cage, and an operating member; saidplug having an interior inlet and a rotative bearing in said cage bymeans of partitions adjacent the plug ports, and a passage exteriorly ofsaid plug permitting fluid flow between the cage and plug for exhaustfrom said cylinder.

2. In a machine of the character described in combination, a reversingvalve comprising. a cage having a pair of ports anda third port forexhaust, a hollow plug rotatively mounted in said cage having portscapable of alternate registration with the said pair of cage ports,valve partitions bordering said plug ports and a third partition on saidplug co-operative with the said exhaust port, and means for effectingarelative rotative movement of-said vplug and cage; the

'- ports and partitions belng'so constructed and spaced as to effectcommunication between one of said pair of cage ports and the exhaustports through a passage formed .between the plug and cage around thesaid partitions and simultaneously effect registration of the other ofsaid pair of cage ports with its co-operating plug port.-

3. In a reversing valve, acage having a rotary bore and three ports oneof which is an exhaust port, a hollow plug rotative in said cage havinga body of general exterior diameter less than the bore of said cage,partitions on said body adjusting the same to an easy rotative fit insaid cage, ports in two of said partitions alternately registrable withtwo cage ports, the partitions and ports being so spaced and arrangedthat when one co-operating pair of ports is registered an exhaustpassage is established from the third cage port completely around theplug to the exhaust port of said cage, and a valve inlet opposite thehollow end of said plug.

4:. In a reversing valve a cage having a rotary bore and three ports oneof which is an exhaust port, a hollow plug rotative in said cage havinga body-of general exterior diameter less than the bore of said cage,partitions on said body adjusting the same to an easy rotative fit insaid cage, ports in two of said partitions alternately registrable withthe two cage ports, the partitions and ports being so spaced andarranged that when one co-operating pair of ports is registered anexhaust passage is established from the third cage port completelyaround the plug to the exhaust port of said cage, a valve inlet oppositethe hollow end of said.plug, and an operating device for causingrelative rotation of said plug and cage comprising a quick throwmechanism and stop whereby registration of the other set of co-operatingports is effected.

5. In a reversing valve for a hydraulic cylinder in combination, a valvehousing, openings therein adapted to communicate with opposite ends ofthe cylinder, inlet and exhaust openings in said housing a cage having apair of ports respectively communicating with the said openings to saidcylinder and a third port communicating with the exhaust, a hollow plughaving a body of less diameter than the cage interior and provided witha plurality of spaced partitions exteriorly to fit the cage, two of saidpartitions having each a port adapted for registration with one or theother of said pair of cage ports, said ports and partitions being soarranged as to open an exhaust passage around the plug interiorly of thecage while registration is -maintained between either set ofco-operating ports.

6. In a reversing valve, in combination, a cage having two cylinderports and an exhaust port, a plug having two cylinder ports co-operativerespectively with the cylinder ports of the cage, means permitting fluidflow from the interior of said plu through a pair of co-operating portsand having provision for simultaneously k exhausting fluid through theother cylinder port of said cage around the exterior of the plug to thecage exhaust port.

7. In a reversing valve, a cage having a rotary bore and three ports oneof which is an exhaust port, a hollow plug rotative in said cage havinga body of general exterior diameter less than the bore of said cage,partitions on said plug adapting the same to an easy rotative fit insaid cage, ports in two of said partitions alternately registrable withthe two cage ports, the partitions and ports being so spaced andarranged that when one co-operating pair of ports is registered anexhaust passage is established from the third cage port completelyaround the plug to the exhaust port of said cage, a valve inlet oppositethe hollow end of said plug, and means for operating said plug withinsaid cage.

- JAMES E. GREENSMITH.

